Packaging to improve shelflife of insulation products

ABSTRACT

Fibrous insulation products have a binder composition that may include a carbohydrate and a crosslinking agent, and potentially other optional ingredients. The shelf life and physical properties of fibrous insulation products, particularly those having bio-based binders, can be improved by packaging that completely envelopes and seals the fibrous product from exposure to atmospheric conditions. Exemplary envelopes disclosed include sealed bags, double stretch wrap and stretch hoods. Properties that can be improved include recovery of loft, restoring force and tensile strength among others.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is related to U.S. patent application Ser. No.13/037,725 titled “INSULATIVE PRODUCTS HAVING BIO-BASED BINDERS” filedMar. 1, 2011, and to applications to which it is in turn related, theentire contents of which are expressly incorporated herein by reference.

TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY OF THE INVENTION

The present invention relates generally to fibrous insulation productsand, more particularly, to packaging that improves the physicalproperties of fibrous insulation products, especially products thatcontain a bio-based binder.

BACKGROUND OF THE INVENTION

Conventional fibers are useful in a variety of applications includingreinforcements, textiles, and acoustical and thermal insulationmaterials. Although mineral fibers (e.g., glass fibers) are typicallyused in insulation products and non-woven mats, depending on theparticular application, organic fibers such as polypropylene, polyester,and multi-component fibers may be used alone or in combination withmineral fibers in forming the insulation product or non-woven mat.

Fibrous insulation is typically manufactured by fiberizing a moltencomposition of polymer, glass, or other mineral and spinning fine fibersfrom a fiberizing apparatus, such as a rotating spinner. To form aninsulation product, fibers produced by the rotating spinner are drawndownwardly from the spinner towards a conveyor by a blower. As thefibers move downward, a binder material is sprayed onto the fibers andthe fibers are collected into a high loft, continuous blanket on theconveyor. The binder material gives the insulation product resiliencyfor recovery after packaging and provides stiffness and handleability sothat the insulation product can be handled and applied as needed in theinsulation cavities of buildings. The binder composition also providesprotection to the fibers from interfilament abrasion and promotescompatibility between the individual fibers.

The blanket containing the binder-coated fibers is then passed through acuring oven and the binder is cured to set the blanket to a desiredthickness. After the binder has cured, the fiber insulation may be cutinto lengths to form individual insulation products, and the insulationproducts may be packaged for shipping to customer locations.

It has been found that certain physical properties of fibrous insulationproducts may deteriorate over aging or storage time. This isparticularly true of products stored under conditions of high heat andhumidity, and has been found to be a problem for phenolic orformaldehyde based binders as well as bio-based binders. The presentinvention provides solutions to such problems.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide packaging forfibrous insulation product that includes a plurality of randomlyoriented fibers and a binder composition applied to at least a portionof the fibers and interconnecting the fibers.

Thus, in a first aspect the invention provides a method of improving thephysical properties of a fibrous insulation product subjected to storagein ambient conditions, the method comprising:

-   applying a binder to the fibrous product;-   curing the binder to form a cured fibrous insulation product having    defined physical properties; and-   packaging the cured fibrous product in a package that preserves the    defined physical properties.

In this first aspect, the defined physical property of the fibrousproduct may be any or all of (a) recovery of loft, (b) restoring force,and (c) tensile strength; and the package has a permeance not more thanabout 0.9 g/hr-ft²-in Hg; or not more than about 0.5 g/hr-ft²-in Hg; orbetween about 0.05 and about 0.5 g/hr-ft²-in Hg.

In a second aspect the invention provides a method of minimizing therecovery degradation of a fibrous insulation product having a curedbinder, the method comprising storing the cured fibrous product in apackage that has a permeance of not more than about 0.9 g/hr-ft²-in Hg.

In both aspects, the permeance is preferably less than about 0.5g/hr-ft²-in Hg, and may be in the range from about 0.05 to about 0.5g/hr-ft²-in Hg. Furthermore, in each aspect, the package has elasticityin the range of about 400% to about 1000%; a tensile strength in therange of about 3500 to about 8400 psi; and a tear strength in the rangeof 300 to about 900 grams/mil nominal thickness. The package may be madeof a composition selected from low-density polyethylene (LDPE) or acopolymer of LDPE with polyvinylchloride, polypropylene or polyamides.The packaging may comprise a bag, a double stretch wrap or a stretchhood, as those terms are defined herein.

The foregoing and other objects, features, and advantages of theinvention will appear more fully hereinafter from a consideration of thedetailed description that follows. It is to be expressly understood,however, that the drawings are for illustrative purposes and are not tobe construed as defining the limits of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages of this invention will be apparent upon consideration ofthe following detailed disclosure of the invention, especially whentaken in conjunction with the accompanying drawings wherein:

FIG. 1 is perspective view illustrating a first embodiment of theinvention;

FIG. 2 is perspective view illustrating a second embodiment of theinvention;

FIG. 3 is perspective view illustrating a third embodiment of theinvention;

FIG. 4 is cross sectional view taken along line 4-4 of FIG. 3,illustrating overlapping portions of the packaging; and

FIG. 5 is a graph of data from Example 17.

DETAILED DESCRIPTION OF THE INVENTION

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which the invention belongs. Although any methods andmaterials similar or equivalent to those described herein can be used inthe practice or testing of the present invention, the preferred methodsand materials are described herein. All references cited herein,including published or corresponding U.S. or foreign patentapplications, issued U.S. or foreign patents, and any other references,are each incorporated by reference in their entireties, including alldata, tables, figures, and text presented in the cited references.

In the drawings, the thickness of the lines, layers, and regions may beexaggerated for clarity. It will be understood that when an element suchas a layer, region, substrate, or panel is referred to as being “on”another element, it can be directly on the other element or interveningelements may also be present. Also, when an element is referred to asbeing “adjacent” to another element, the element may be directlyadjacent to the other element or intervening elements may be present.The terms “top”, “bottom”, “side”, and the like are used herein for thepurpose of explanation only. Like numbers found throughout the figuresdenote like elements. It is to be noted that the phrase “binder”,“bio-based binder”, “binder composition”, and “binder formulation” maybe used interchangeably herein.

“Mineral fibers” refers to any mineral material that can be melted toform molten mineral that can be drawn or attenuated into fibers. Glassis the most commonly used mineral fiber for fibrous insulation purposesand the ensuing description will refer primarily to glass fibers, butother useful mineral fibers include rock, slag and basalt.

“Product properties” refers to a battery of testable physical propertiesthat insulation batts possess. These may include at least the followingcommon properties:

-   -   “Recovery”—which is the ability of the batt or blanket to resume        it's original or designed thickness following release from        compression during packaging or storage. It may be tested by        measuring the post-compression height of a product of known or        intended nominal thickness, or by other suitable means.    -   “Stiffness” or “sag”—which refers to the ability of a batt or        blanket to remain rigid and hold its linear shape. It is        measured by draping a fixed length section over a fulcrum and        measuring the angular extent of bending deflection, or sag.        Lower values indicate a stiffer and more desirable product        property. Other means may be used.    -   “Tensile Strength”—which refers to the force that is required to        tear the fibrous product in two. It is typically measured in        both the machine direction (MD) and in the cross machine        direction (“CD” or “XMD”).    -   “Lateral weight distribution” (LWD or “cross weight”)—which is        the relative uniformity or homogeneity of the product throughout        its width. It may also be thought of as the uniformity of        density of the product, and may be measured by sectioning the        product longitudinally into bands of equal width (and size) and        weighing the band, by a nuclear density gauge, or by other        suitable means.    -   “Vertical weight distribution” (VWD)—which is the relative        uniformity or homogeneity of the product throughout its        thickness. It may also be thought of as the uniformity of        density of the product, and may be measured by sectioning the        product horizontally into layers of equal thickness (and size)        and weighing the layers, by a nuclear density gauge, or by other        suitable means.        Of course, other product properties may also be used in the        evaluation of final product, but the above product properties        are ones found important to consumers of insulation products.

Binder Compositions

The present invention encompasses both traditional phenolic-formaldehydebinders, as well as the more recent formaldehyde-free binders, includingpolyacrylic binders and carbohydrate, starch or bio-based binders.Carbohydrate bio-based binders are described herein as an exemplaryembodiment.

In one exemplary embodiment, a bio-based component is a carbohydrate andthe binder includes a carbohydrate and a crosslinking agent. Typicallythe carbohydrate has reactive hydroxyl groups and the crosslinking agenthas reactive carboxyl groups. In some exemplary embodiments, thecarbohydrate-based binder composition also includes a coupling agent, aprocess aid agent, an extender, a pH adjuster, a catalyst, acrosslinking density enhancer, a deodorant, an antioxidant, a dustsuppressing agent, a biocide, a moisture resistant agent, orcombinations thereof. The binder may be used in the formation ofinsulation materials and non-woven chopped strand mats. In addition, thebinder is free of added formaldehyde. Further, the binder compositionhas a reduction in particulate emission compared to conventionalphenol/urea/formaldehyde binder compositions. The inventive binder mayalso be useful in forming particleboard, plywood, and/or hardboards.

In one or more exemplary embodiment, the binder includes at least onecarbohydrate that is natural in origin and derived from renewableresources. For instance, the carbohydrate may be derived from plantsources such as legumes, maize, corn, waxy corn, sugar cane, milo, whitemilo, potatoes, sweet potatoes, tapioca, rice, waxy rice, peas, sago,wheat, oat, barley, rye, amaranth, and/or cassava, as well as otherplants that have a high starch content. The carbohydrate polymer mayalso be derived from crude starch-containing products derived fromplants that contain residues of proteins, polypeptides, lipids, and lowmolecular weight carbohydrates. The carbohydrate may be selected frommonosaccharides (e.g., xylose, glucose, and fructose), disaccharides(e.g., sucrose, maltose, and lactose), oligosaccharides (e.g., glucosesyrup and fructose syrup), and polysaccharides and water-solublepolysaccharides (e.g., pectin, dextrin, maltodextrin, starch, modifiedstarch, and starch derivatives).

The carbohydrate polymer may have a number average molecular weight fromabout 1,000 to about 8,000. Additionally, the carbohydrate polymer mayhave a dextrose equivalent (DE) number from 2 to 20, from 7 to 11, orfrom 9 to 14. The carbohydrates beneficially have a low viscosity andcure at moderate temperatures (e.g., 80-250° C.) alone or withadditives. The low viscosity enables the carbohydrate to be utilized ina binder composition. In exemplary embodiments, the viscosity of thecarbohydrate may be lower than 500 cps at 50% concentration and between20 and 30° C. The use of a carbohydrate in the inventive bindercomposition is advantageous in that carbohydrates are readily availableor easily obtainable and are low in cost.

In at least one exemplary embodiment, the carbohydrate is awater-soluble polysaccharide such as dextrin or maltodextrin. Thecarbohydrate polymer may be present in the binder composition in anamount from about 40% to about 95% by weight of the total solids in thebinder composition, from about 50% to about 95% by weight of the totalsolids in the binder composition, from about 60% to about 90%, or fromabout 70% to about 85%. As used herein, % by weight indicates % byweight of the total solids in the binder composition.

In addition, the binder composition contains a crosslinking agent. Thecrosslinking agent may be any compound suitable for crosslinking thecarbohydrate. In exemplary embodiments, the crosslinking agent has anumber average molecular weight greater than 90, from about 90 to about10,000, or from about 190 to about 4,000. In some exemplary embodiments,the crosslinking agent has a number average molecular weight less thanabout 1000. Non-limiting examples of suitable crosslinking agentsinclude polycarboxylic acids (and salts thereof), anhydrides, monomericand polymeric polycarboxylic acid with anhydride (i.e., mixedanhydrides), citric acid (and salts thereof, such as ammonium citrate),1,2,3,4-butane tetracarboxylic acid, adipic acid (and salts thereof),polyacrylic acid (and salts thereof), and polyacrylic acid based resinssuch as QXRP 1734 and Acumer 9932, both commercially available from TheDow Chemical Company. In exemplary embodiments, the crosslinking agentmay be any monomeric or polymeric polycarboxylic acid, citric acid, andtheir corresponding salts. The crosslinking agent may be present in thebinder composition in an amount up to about 50% by weight of the bindercomposition. In exemplary embodiments, the crosslinking agent may bepresent in the binder composition in an amount from about 5.0% to about40% by weight of the total solids in the binder composition or fromabout 10% to about 30% by weight.

Optionally, the binder composition may include a catalyst to assist inthe crosslinking. The catalyst may include inorganic salts, Lewis acids(i.e., aluminum chloride or boron trifluoride), Bronsted acids (i.e.,sulfuric acid, p-toluenesulfonic acid and boric acid) organometalliccomplexes (i.e., lithium carboxylates, sodium carboxylates), and/orLewis bases (i.e., polyethyleneimine, diethylamine, or triethylamine).Additionally, the catalyst may include an alkali metal salt of aphosphorous-containing organic acid; in particular, alkali metal saltsof phosphorus acid, hypophosphorus acid, or polyphosphoric acids.Examples of such phosphorus catalysts include, but are not limited to,sodium hypophosphite, sodium phosphate, potassium phosphate, disodiumpyrophosphate, tetrasodium pyrophosphate, sodium tripolyphosphate,sodium hexamethaphosphate, potassium phosphate, potassiumtripolyphosphate, sodium trimetaphosphate, sodium tetramethaphosphate,and mixtures thereof. In addition, the catalyst or cure accelerator maybe a fluoroborate compound such as fluoroboric acid, sodiumtetrafluoroborate, potassium tetrafluoroborate, calciumtetrafluoroborate, magnesium tetrafluoroborate, zinc tetrafluoroborate,ammonium tetrafluoroborate, and mixtures thereof. Further, the catalystmay be a mixture of phosphorus and fluoroborate compounds. Other sodiumsalts such as, sodium sulfate, sodium nitrate, sodium carbonate may alsoor alternatively be used as the catalyst/accelerator. The catalyst orcure accelerator may be present in the binder composition in an amountfrom about 0% to about 10% by weight of the total solids in the bindercomposition, or from about 1.0% to about 5.0% by weight, or from about3.0% to about 5.0% by weight.

The binder may contain many additional optional or additive ingredientssuch as coupling agents, processing aids, surfactants, corrosioninhibitors, biocidal agents, pH adjusters or buffers, moistureresistance agents, dust suppressors, fillers or extenders, flameretardants, dyes, pigments, fillers, colorants, UV stabilizers, thermalstabilizers, anti-foaming agents, anti-oxidants, emulsifiers,preservatives (e.g., sodium benzoate), and the like. Such optionalingredients are described more fully in the literature, including U.S.patent application Ser. No. 13/037,725 titled “INSULATIVE PRODUCTSHAVING BIO-BASED BINDERS” filed Mar. 1, 2011 and U.S. patent applicationSer. No. 12/900,540, filed Oct. 8, 2010, which claims priority benefitsfrom U.S. Provisional Patent Application Ser. No. 61/250,187entitled“Bio-Based Binders For Insulation And Non-Woven Mats” filed Oct. 9,2009, the entire contents of each of which are expressly incorporatedherein by reference.

The binder further includes water to dissolve or disperse the activesolids for application onto the fibers. Water may be added in an amountsufficient to dilute the aqueous binder composition to a viscosity thatis suitable for its application to the fibers and to achieve a desiredsolids content on the fibers. In particular, the binder composition maycontain water in an amount from about 50% to about 98.0% by weight ofthe total solids in the binder composition.

The binder composition may be made by dissolving or dispersing thecrosslinking agent in water to form a mixture. Next, the carbohydratemay be mixed with the crosslinking agent in the mixture to form thebinder composition. If desired, a cure accelerator (i.e., catalyst) maybe added to the binder composition. The binder composition may befurther diluted with water to obtain a desired amount of solids. Ifnecessary, the pH of the mixture may be adjusted to the desired pH levelwith organic and inorganic acids and bases.

In the broadest aspect of the invention, the carbohydrate-based bindercomposition is formed of a carbohydrate (e.g., maltodextrin) and acrosslinking agent (e.g., polyacrylic acid or citric acid)—as seen inSample A of Table 1. Samples B and C add other optional ingredients likea processing aid or polyol, or a catalyst or cure accelerator insuitable range amounts. The range of components used in the inventivebinder composition according to embodiments of the invention set forthin Table 1 is given in weight percent of total solids (i.e. dry weight5%).

TABLE 1 Component Sample A Sample B Sample C Carbohydrate 60.0-95.05.0-90.0 5.0-90.0 Crosslinking Agent  5.0-40.0 5.0-40.0 5.0-40.0 ProcessAid Agent 0 1.0-40.0 1.0-40.0 Catalyst/Cure 0 0 1.0-5.0  AcceleratorFibrous Products with Bio-Based Binders

In one exemplary embodiment, the binder composition is used to form afibrous product, typically an insulation product. Fibrous products aregenerally formed of matted inorganic fibers bonded together by a curedthermoset polymeric material. Examples of suitable inorganic fibersinclude glass fibers, wool glass fibers, and ceramic fibers. Optionally,other reinforcing fibers such as natural fibers and/or synthetic fiberssuch as polyester, polyethylene, polyethylene terephthalate,polypropylene, polyamide, aramid, and/or polyaramid fibers may bepresent in the insulation product in addition to the glass fibers. Theterm “natural fiber” as used in conjunction with the present inventionrefers to plant fibers extracted from any part of a plant, including,but not limited to, the stem, seeds, leaves, roots, or phloem. Examplesof natural fibers suitable for use as the reinforcing fiber materialinclude basalt, cotton, jute, bamboo, ramie, bagasse, hemp, coir, linen,kenaf, sisal, flax, henequen, and combinations thereof. Insulationproducts may be formed entirely of one type of fiber, or they may beformed of a combination of types of fibers. For example, the insulationproduct may be formed of combinations of various types of glass fibersor various combinations of different inorganic fibers and/or naturalfibers depending on the desired application for the insulation. Theembodiments described herein are with reference to insulation productsformed primarily of glass fibers.

The term “fibrous products” is general and encompasses a variety ofcompositions, articles of manufacture, and manufacturing processes.“Fibrous products” may be characterized and categorized by manydifferent properties; density for example, which may range broadly fromabout about 0.2 pounds/cubic foot (“pcf”) to as high as about 10 pcf,depending on the product. Low density flexible insulation batts andblankets typically have densities between about 0.2 pcf and about 5 pcf,more commonly from about 0.3 to about 4 pcf. Fibrous products alsoinclude higher density products having densities from about 1 to about10 pcf, more typically from about 2 or 3 pcf to about 8 pcf, such asboards and panels or formed products. Higher density insulation productsmay be used in industrial and/or commercial applications, including butnot limited to metal building insulation, pipe or tank insulation,insulative ceiling and wall panels, duct boards and HVAC insulation,appliance and automotive insulation, etc.

Another property useful for categorization is the rigidity of theproduct. Residential insulation batts are typically quite flexible andthey can be compressed into rolls or batts while recovering their “loft”upon decompression. In contrast, other fibrous products, such as ceilingtiles, wall panels, foundation boards and certain pipe insulation tomention a few, are quite rigid and inflexible by design. These productswill flex very little and are unlikely to be adapted or conformed to aparticular space.

Shape is another important property. Some fibrous products are flexible,as noted and can be forced to assume conforming shapes, while other areformed and shaped for a specific purpose. In some embodiments, the shapeis substantially planar, as in duct boards, ceiling tiles and some wallinsulation. In other embodiments, the fibrous insulation product ismanufactured with a particular shape (e.g. cylindrical) suitable for aparticular size conduit, pipe or tank. In other cases, specific shapesand cutouts, often die-cut, are included in certain appliance insulationproducts, automotive insulation products and the like. Finally, othershapes may be created with nonwoven textile insulation products.

Other classifications of fibrous insulation products can include themethod of manufacture. The manufacture of glass fiber insulation may becarried out in a continuous process by rotary fiberization of moltenglass, immediately forming a fibrous glass pack on a moving conveyor,and curing the binder on the fibrous glass insulation batt to form aninsulation blanket. Rotary fiberization and other manufacturingprocesses are described in the literatures and the details need not berepeated here.

The binder may be present in an amount from about 1% to 30% by weight ofthe total fibrous product, more usually from about 2% to about 20% orfrom about 3% to about 14%. Binder content of the fibrous products istypically measured by loss on ignition or “LOI” of the cured product.

While in a curing oven, the insulation pack may be compressed by upperand lower foraminous oven conveyors to form a fibrous insulationblanket. It is to be appreciated that the insulation blanket also has anupper surface and a lower surface. In particular, the insulation blankethas two major surfaces, typically a top and bottom surface, and twominor or side surfaces, and is oriented so that the major surfaces havea substantially horizontal orientation. The upper and lower ovenconveyors may be used to compress the insulation pack to give theinsulation blanket a predetermined thickness.

The curing oven may be operated at a temperature from about 100° C. toabout 325° C., or from about 250° C. to about 300° C. The insulationpack may remain within the oven for a period of time sufficient tocrosslink (cure) the binder and form the insulation blanket. Theinventive binder composition cures at a temperature that is lower thanthe curing temperature of conventional formaldehyde binders. This lowercuring temperature requires less energy to heat the insulation pack, andnon-woven chopped strand mat described in detail below, which results inlower manufacturing costs.

In some exemplary embodiments, the insulation blanket that emerges fromthe oven is rolled onto a take-up roll or cut into sections having adesired length. It may or may not be faced with a barrier material.Optionally, the insulation blanket may be slit into layers and by aslitting device and then cut to a desired length.

A significant portion of the insulation placed in the insulationcavities of buildings is in the form of insulation blankets rolled frominsulation products such as is described above. Faced insulationproducts are installed with the facing placed flat on the edge of theinsulation cavity, typically on the interior side of the insulationcavity. Insulation products where the facing is a vapor retarder arecommonly used to insulate wall, floor, or ceiling cavities that separatea warm interior space from a cold exterior space. The vapor retarder isplaced on one side of the insulation product to retard or prohibit themovement of water vapor through the insulation product.

Formed or shaped products may include a further step, optionally duringcure, that molds or shapes the product to its specific final shape.Rigid boards are a type of shaped product, the shape being planar. Othershaped products may be formed by dies or molds or other formingapparatus. Rigidity may be imparted by the use of higher density offibers and/or by higher levels of binder application. As an alternativeto rotary fiberizing, some fibrous insulation products, particularlyhigher density, non-woven insulation products, may be manufactured by anair-laid or wet-laid process using premade fibers of glass, otherminerals or polymers that are scattered into a random orientation andcontacted with binder to form the product.

In other embodiments, the binder composition may be applied to the webby a suitable binder applicator, such as a spray applicator or a curtaincoater. Once the binder has been applied to the web, the binder coatedweb is passed through at least one drying oven to remove any remainingwater and cure the binder composition. The formed fibrous product thatemerges from the oven is an assembly or mat of randomly oriented,dispersed, individual fibers, and may be rolled onto a take-up roll forstorage for later use as illustrated.

In some cases, it is even possible to use scraps of continuous fibers,such as E-glass, and cut them to lengths suitable for fluid-dispersedmanufacturing processes. In one embodiment of textile pipe insulation,lengths of scrap E-glass are cut ranging from about 0.5 to about 6inches, nominally about 2 inches in length. These are dispersed by afluid (water or air), the fluid is removed, and the fibers are sprayedwith a bio-based binder which is cured as before.

Some exemplary fibrous products that can be manufactured using thebio-based binders according to the invention include those illustratedin Table A below.

TABLE A Bio-based binder formulations for representative products*Flexible Metal Duct Building Warm & Ceiling Tile boards Media InsulationDry boards A B C Maltodextrin 65-70 65-70 65-70 65-70 45-50 55-60 CitricAcid 25-30 25-30 25-30 25-30 30-35 25-30 Sodium 2-5 2-5 2-5 2-5 2-5 2-5hypophosphite Glycerol 10-15 Polyglycol  7-10 Surfactant (e.g.   0.1-0.3%    0.1-0.3%    0.1-0.3%    0.1-0.3% SURFYNOL 465)Organopolysiloxane Up to 0.5% Up to 0.5%    0.4-0.5% Up to 0.5% Up to0.5% Up to 0.5% moisture resistance additive (e.g. Polon MR) *In Table Aabove, each ingredient of the binder composition is given as a range oftypical values of percentage of dry weight of the binder composition.

Whereas examples 4, 5, 7, and 12 relate to flexible, light densityresidential insulation, examples 8, 9 and 10 further illustratecommercial fibrous products other than the typical flexible residentialinsulation. A more complete listing of non-residential insulationfibrous products that can be manufactured using a bio-based bindercomposition according to the invention is set forth in Table B, below.

TABLE B Selected Commercial and Industrial Fibrous Products which mayuse a Bio-Based Binder Flexible, Light Density Rigid Pipe InsulationTextile E-glass Rigid Boards Insulation and pipe rolls Nonwoven DensityWide range of densities- Light density - Ranging from Ranging from 3-6pcf Ranging from 0.8 to 4 pcf from 1.5 to 10 pcf 0.3 to 4.0 pcf Bindercontent about 2 to about 20% LOI about 2 to about 13% LOI about 3 toabout 15% LOI about 5 to about 20% LOI Manufacturing Rotary fiberforming process Rotary fiber forming process Rotary fiber formingAir-laid nonwoven process method process plus on or offline molding/pipeformation process Exemplary QUIET R Duct Board Certified R MetalBuilding EVOLUTION Paper-Free QUIET R Textile Duct Owens Corning QUIET RDuct Liner Insulation ASJ Liner Products Board ELAMINATOR ®Pre-Engineered VAPORWICK Insulation DURAFLEX 700 Series Insulation MetalRoof Insulation FIBERGLAS ™ Pipe and Transportation Insul-QuickInsulation MBI Plus Tank Insulation rolls SCR Insulation Board MetalBldg Utility Blanket Curtainwall Unfaced Metal Building InsulationQuietZone Shaftwall for Canada Warm -N -Dri Flexible Duct MediaInsulation Energy Board QUIET R Rotary Duct Liner TremDrain SOFTR DuctWrap FRK Exterior Foundation TIW Types I and II Barrier Board FLEX-Wrapfor pipes and tanks Ceiling Board Blanks H2V Series RA Series SelectSound Thermorange FlameSpread 25 Sonobatts Thermal Batts

There are numerous advantages provided by the inventive binderformulations. For example, unlike conventional urea-formaldehydebinders, inventive binders have a light color after curing (in lowdensity products). In addition, the carbohydrate is natural in originand derived from renewable resources. By lowering or eliminatingformaldehyde emission, the overall volatile organic compounds (VOCs)emitted in the workplace are reduced. Additionally, becausecarbohydrates are relatively inexpensive, the insulation product orchopped fiber mat can be manufactured at a lower cost. Further, thebinder has low to no odor, making it more desirable to work with.

Packaging for Fibrous Products with Bio-Based Binders

The packaging will generally comprise a complete envelope surroundingthe fibrous product. Various illustrative embodiments for packaging aredescribed herein. Referring to a first embodiment, shown in FIG. 1 andreferred to as a “sealed bag”, four rolls 12 of a fibrous insulationproduct are shown initially in an unwrapped state. A sealable bag 14having side walls 16 and a bottom defining an open interior 18 isemployed to form the complete envelope. The rolls 12 are inserted intothe interior 18 of the bag 14 via the open top and the bag is drawntightly closed at the neck 20. The bag is made of materials having theproperties described herein.

In the alternative embodiment shown in FIG. 2 the rolls 12 are wrappedby a first web 22 of packaging material to form a “stretch wrap” (SW)bundle 24 with the ends 26 of the rolls 12 exposed to the atmosphere. Awrapping apparatus (not shown) is configured to install the web 22around the rolls 12. The rolls 12 in the SW bundle 24 are thenreoriented relative to the wrapping apparatus, e.g. by rotating the SWbundle 24 by about 90 degrees while the wrapping apparatus remains inits same orientation or, alternatively, by rotating the wrappingapparatus while the SW bundle 24 remains in its original orientation.After the reorientation of the SW bundle 24, a second web 28 ofpackaging material is wrapped around the SW bundle 24 in a directiontransverse to the direction of the first web 22, forming a sealed“double stretch wrapped,” (DSW) bundle 30 in which no areas of fibrousproduct are exposed to the atmosphere. In the DSW sealed bundle 30 theexposed ends 26 of the stretch wrap bundle 24 have been encased orencapsulated by the second web 28, sealing the envelope about thefibrous product. The second web 28 may be the same material as the firstweb 22, or it may be different. At least one, and optionally both, ofthe webs 22, 28 have the properties described herein.

In a third embodiment, shown in FIG. 3 and referred as a “stretch hood”,the rolls 12 are placed on a first web or slip sheet 32. The slip sheet32 may include perforations 34 for separating the web into sections suchas the section 36. A bag-like envelope or “hood” 38 having side walls40, a top 42 and an open bottom is lowered over the rolls 12. The slipsheet 32 is folded up the sides of the rolls 12 and is tucked under thedescending hood 38 so that the slip sheet 32 and hood side wall 40overlap (as shown at corner 46 in FIG. 4) to form a sealed bundle orenvelope 44. The hood 38 and the slip sheet 32 are made of materialshaving the properties described herein. In addition, the hood 38 may bean elastic material that can either be stretched to fit over the rollsand relaxed to tightly seal the rolls 12, or it may be a material thatcan be shrunk, such as by means of the application of heat.

Certain properties of the packaging have been found to be useful foraccomplishing the advantageous features. These properties and suitableranges are described in the paragraphs that follow. For example, itappears important to keep ambient humidity and moisture from thereaching the fibrous product. Therefore, the permeance of the packagingmaterial is an important factor. Permeance—and its thickness-normalizedcounterpart, permeability—are measures of the rate at which a membraneor film will pass or transmit water vapor. ASTM E96 is one of severalstandard procedures for assessing moisture vapor transmission rates(MVTR). It introduces a membrane or film to two differing moistureenvironments and monitors the flow of water vapor (grains/hour) acrossthe known area (ft²) of the film as the two environments equilibrate.Because the rate of transmission of moisture is dependent, in part, onthe driving force of the vapor pressure (inches Hg), this is alsofactored into the calculation. Thus, the English units for permeance ofa material of given thickness (inches) are grains/hr*ft²*inches Hg orabbreviated to g/hr-ft²-in Hg. This is equivalent to another permeanceunit known as “perms” although the literature often confuses permeanceand permeability when using “perms.” Strictly, permeance is dependent onmaterial thickness and is given along with the material thickness.Permeability, on the other hand, is normalized to a standard thicknessof 1 inch.

The permeance of suitable packaging will generally be less than 0.9grains/hr*ft²*inches Hg, and will typically be less than 0.5. Althoughless permeable materials will work, there is little need to requirepermeance less than about 0.05. Consequently, a useful range ofpermeance is from about 0.05 to about 0.5 grains/hr*ft²*inches Hg, orideally from about 0.05 to about 0.25 grains/hr*ft²*inches Hg. It willbe appreciated that these levels of permeance refer to the total packageand may be achieved by one or more layers of packaging materials. Theselevels of permeance may also be achieved by using thinner or fewerlayers of materials having low permeability, as well as by using thickeror more layers of materials having high permeability. Some examples areprovided below.

In one particular variation, the packaging may have variable permeance,depending on the relative humidity. For example, at higher humiditylevels, e.g. above about 60% relative humidity, the packaging is morepermeable than at lower relative humidity, e.g. below about 30%. Toillustrate, the following potential permeance ranges are provided forthe respective relative humidities (RH):

Relative humidity (%) Permeance (grains/hr*ft²*inches Hg)   <20% RH0.05-0.25 21-40% RH 0.09-0.5  41-60% RH 0.12-0.7  61-80% RH 0.3-0.8  >81% RH 0.5-0.9

Materials having a variable permeance feature are described for use as ahouse vapor barrier in U.S. Pat. No. 7,829,197 to Chen, et al. (DuPont).This material is claimed to have a wet cup permeance of 10 to 75 timesthe dry cup permeance, wet and dry being defined as 75% and 25% relativehumidity respectively. This feature allows for internal moisture toescape if packaged under high humidity conditions.

Another property that becomes important for packaging—especially for theSW and DSW embodiments—is the elasticity of the wrapping or packagingmaterial. Elasticity is usefully measured according to ASTM D882 as thepercentage a material can be stretch beyond its original length withoutbreaking; this is useful in providing compression of the fibrousproducts and reducing storage space requirements. Packaging materialsmay or may not be pre-stretched during manufacturing, for example about85% to 150% more than original length. After this pre-stretching step,further stretching is generally desirable: elasticities of about 300% upto about 1000% are useful, and in particular elasticity may be in therange of about 400 to about 800%.

A third property important for packaging material is the strength of thefilm. This can be measured two ways: (1) as a tensile strength—(ASTM D822) the force necessary to create a break when an elongation force isapplied at the ends of the film (i.e. pulled from two ends linearly withthe film); and (2) as a tear strength—(ASTM D1922) the force necessaryto create a break when applied in a direction normal (approximatelyperpendicular) to the film (e.g. an edge is pulled or torqued inopposing directions). Tear strength may be measured in a machinedirection (MD) and a cross-machine or transverse direction (TD) but thisdirectionality is not critical to the invention.

Tensile strengths of suitable packaging materials generally range fromabout 3500 to about 8400 pounds/square inch (psi). In some embodiments,the tensile strength may be from about 3500 to about 6000 psi; while inother embodiments, the tensile strength may be from about 6000 to about8400 psi. The tear strength is generally in the range of from about 100to 900 g/mil nominal thickness. In some embodiments (e.g. bags), thetear strength can be lower and may be from about 100 to about 600 g/milnominal thickness; while in other embodiments (e.g. stretch wraps), thetensile strength should be higher, e.g. from about 600 to about 900g/mil nominal thickness.

A fourth factor relevant to packaging properties is the ability of thematerial to cling to itself, also known as a coefficient of friction(COF), as measured by ASTM 1894. This is less important for bags thanfor stretch wrap. Bags may have a COF in the range of from about 0.1 toabout 0.6, or from about 0.25 to about 0.45. Stretch wrap, on the otherhand, should be “stickier” and have a COF of at least 0.6 and preferablyat least 1.0.

Another property of packaging materials is the degree to which thematerial is clear or opaque. Generally, clear or nearly clear materialsare preferred for visibility to the fibrous products inside. ASTM D1003describes the degree of transparency in terms of percent, ranging from 0(clear) to100% (opaque). Generally a haze of 20% or less is desirable.

Thickness is another property of packaging materials and it impactsother properties mentioned above, such as permeance, strength,elasticity, etc. Thicknesses are generally in the range from about 0.25to about 5 mils (one mil=0.001 inch); or from about 0.5 to about 3.5mils

The packaging materials useful with the invention may be made of anymaterial that meets the physical properties described above. Applicantshave found that certain polymeric plastic materials are suitable. Someexamples of suitable polymeric plastics include, polyethylene (PE), bothhigh-density (HDPE) and low-density (LDPE) versions; polypropylene (PP);biaxially-oriented polypropylene (BOPP); polyvinylidene chloride (PVDC);copolymers of PE and PVC; copolymers of PE and PP; copolymers of PE andpolyamides. In copolymer combinations, LDPE may be used as the PEcomponent.

Having generally described this invention, a further understanding canbe obtained by reference to certain specific examples illustrated belowwhich are provided for purposes of illustration only and are notintended to be all inclusive or limiting unless otherwise specified.

EXAMPLES Examples 1-14

Examples 1 to 14 herein are incorporated from Examples 1-14, includingtables 4-33 that appear in U.S. patent application Ser. No. 13/037,725titled “INSULATIVE PRODUCTS HAVING BIO-BASED BINDERS” filed Mar. 1,2011, already incorporated herein.

Example 15

Various packaging materials are obtained having the physical propertieslisted in Table 34.

TABLE 34 Representative Packaging Material Properties Sample 1 Sample 2Sample 3 Sample 4 (Bag) (Bag) (DSW film) (DSW film) nominal 2.0 2.0 1.51.5 thickness (mils) No. of layers 1 1 3 2 composition LDPE LDPE/PP LDPEPE copolymer permeance 0.25 0.3 0.15 0.3 g*in/hr*ft²*in Hg elasticity(%) 700% 800% 600% 550% tensile/elongation 4500 5000 7000 7500 (psi)tear (g/mil) 875 900 600 575 Coeff. of Friction 0.35 0.4 1.5 2.0 haze(%)  14%  16%  6%  7%

Example 16

Flexible duct media (FDM) is a type of fibrous insulation that is oftenused around flexible conduit or tubing. It is generally available inrolls designated with R values 4.2, 6 or 8 and having nominal thicknessof 1.25, 2, and 2.25 inches, respectively. FDM was produced with abio-based binder according to the invention in R6 thicknesses (nominally2 inches) and placed in various types of packaging for testing. Thecomparison points were the recoveries achieved after storage at ambientconditions for 7 days (“ambient x7d”). The experimental conditionstested include accelerated temperature and humidity tests as well asvariations in time (x21 days vs. x7 days). For example, the conditionlabeled “73/92” indicates a temperature of 73F and relative humidity(RH) of 92%; and the condition labeled “73/92-92/50” indicates a cycledtemperature and humidity profile simulating day and night in a humidarea of the country; i.e. 73F with 92% RH by night and 92F with 50% RHby day. Products were sampled and tested at 7 days (“x7d”) and at 21days (“x21d”). The controlled variables were stretch wrap bundlepackaging (SW) and double wrapped sealed bundle packaging (DSW) asdescribed above. The data presented in Table 35 are the averages of 18measurements at three longitudinal positions times two verticallocations on four different rolls (18×3×2×4=432 total values) for eachcondition. Percent recovery degradation is calculated as the differencein recovery height (vs. ambient x7d) divided by the initial recoveryheight at ambient x7d.

TABLE 35 Recovery Data Summary Average Avg % Recovery degrada- Thick-Std. 95% tion vs Binder and Condition ness Dev. CI ambient x7Bio-based-SW-ambient x7d 2.41 0.07 0.12 Bo-based-SW-ambient x21d 2.380.06 0.09 1.2 Bo-based-SW-73/92 x7d 2.10 0.01 0.02 13.0Bo-based-SW-73/92 x21d 1.93 0.02 0.04 20.0 Bo-based-SW-73/92-92/50 x7d2.13 0.01 0.02 11.7 Bo-based-SW-73/92-92/50 x21d 2.00 0.01 0.02 17.1Bo-based-DSW-ambient x7d 2.59 0.03 0.05 Bo-based-DSW-ambient x21d 2.500.04 0.06 3.3 Bo-based-DSW-73/92 x7d 2.54 0.04 0.06 1.8Bo-based-DSW-73/92 x21d 2.21 0.04 0.06 14.6 Bo-based-DSW-73/92-92/ 2.330.02 0.02 10.0 50 x7d Bo-based-DSW-73/92-92/ 2.27 0.03 0.06 12.3 50 x21d

The data show that, for all control variables, a small amount (e.g.about 1 to 3%) of recovery degradation occurred over the time lapse ofan additional 14 days from 7 to 21 days. However, the DSW packagingperformed better than the SW packaging in protecting against recoverydegradation for bio-based binder products exposed to high temperatureand humidity conditions.

Example 17

FDM was produced with a bio-based binder according to the invention inR6 thicknesses (nominally 2 inches) and placed in various types ofpackaging for testing. The experimental condition “73/92/3” includesexposure to accelerated temperature and humidity e.g. 73F and 92%relative humidity (RH) for 3 days when recovery was again tested. Thecontrolled packaging variables were sealed bags, stretch wrap bundlepackaging (SW) and double wrapped sealed bundle packaging (DSW) asdescribed above relative to ambient conditions. The data are presentedin FIG. 5.

FIG. 5 shows that both the DSW packaging and the enclosed bags performedbetter than the SW packaging and about as well as the ambient product.

Example 18

FDM was produced with a phenolic binder in R6 thicknesses (nominally 2inches) and was tested initially at ambient conditions. These productswere then exposed to varying environmental conditions for testing.Recovery was tested again at the end of the specified period. The dataare presented in Table 36, and show that products having phenolic binderundergo a similar loss of physical properties upon exposure to hot andhumid conditions, and thus may be improved with the packaging of theinvention.

TABLE 36 Recovery Data Summary- phenolic binder Average Recovery Std.Condition Thickness (inches) Dev. ambient 2.16 0.05 92/50/3 2.12 0.0573/93-92/50-3 2.01 0.10 73/93-92/50-7 1.92 0.16 55/90/3 2.03 0.1255/90/7 1.92 0.05 73/92/3 1.98 0.13 73/92/7 1.96 0.02 90/90/3 1.90 0.0390/90/7 2.00 0.12

The invention of this application has been described above bothgenerically and with regard to specific embodiments. Although theinvention has been set forth in what is believed to be the preferredembodiments, a wide variety of alternatives known to those of skill inthe art can be selected within the generic disclosure. The invention isnot otherwise limited, except for the recitation of the claims set forthbelow.

What is claimed is:
 1. A method of improving the physical properties ofa fibrous insulation product, the method comprising: applying a binderto the fibrous product; curing the binder to form a cured fibrousinsulation product having defined physical properties; and packaging thecured fibrous product in a package that preserves the defined physicalproperties.
 2. The method of claim 1 wherein the package for thepackaging step is selected from a sealable bag, a double wrapped packageand a stretch hood.
 3. The method of claim 2, wherein the binder is abio-based binder.
 4. The method of claim 1 wherein the defined physicalproperty is at least one property selected from recovery of loft,restoring force, and tensile strength.
 5. The method of claim 1 whereinthe package is made of a polymer selected from low-density polyethylene(LDPE) or a copolymer of LDPE with polyvinylchloride, polypropylene orpolyamides.
 6. The method of claim 1 wherein the package has a permeancenot more than about 0.9 g/hr-ft²-in Hg.
 7. The method of claim 6 whereinthe package has a permeance not more than about 0.5 g/hr-ft²-in Hg. 8.The method of claim 7 wherein the package has a permeance between about0.05 and about 0.5 g/hr-ft²-in Hg.
 9. The method of claim 6 wherein thepackage has a permeance that varies with the relative humidity,permeance being greater at higher humidity.
 10. The method of claim 1wherein the package is made of a material having elasticity in the rangeof about 400% to about 1000%.
 11. A method of minimizing the recoverydegradation of a fibrous insulation product having a cured binder, themethod comprising: storing the cured fibrous product in a package thathas a permeance not more than about 0.9 g/hr-ft²-in Hg.
 12. The methodof claim 10 wherein the package has a permeance not more than about 0.5g/hr-ft²-in Hg.
 13. The method of claim 12 wherein the package has apermeance between about 0.05 and about 0.5 g/hr-ft²-in Hg.
 14. Themethod of claim 11 wherein the package has elasticity in the range ofabout 400% to about 1000%.
 15. The method of claim 11 wherein thepackage has tensile strength in the range of about 3500 to about 8400psi.
 16. The method of claim 11 wherein the package has tear strength inthe range of 300 to about 900 grams/mil nominal thickness.
 17. Themethod of claim 11 wherein the package is selected from a sealable bag,a double wrapped package and a stretch hood.
 19. The method of claim 11wherein the package is a stretch hood.
 20. The method of claim 11wherein the package is made of a polymer selected from low-densitypolyethylene (LDPE) or a copolymer of LDPE with polyvinylchloride,polypropylene or polyamides.